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Barrier.h

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/****************** <VPR heading BEGIN do not edit this line> *****************
 *
 * VR Juggler Portable Runtime
 *
 * Original Authors:
 *   Allen Bierbaum, Patrick Hartling, Kevin Meinert, Carolina Cruz-Neira
 *
 * -----------------------------------------------------------------
 * File:          $RCSfile: Barrier.h,v $
 * Date modified: $Date: 2004/01/28 21:52:09 $
 * Version:       $Revision: 1.11 $
 * -----------------------------------------------------------------
 *
 ****************** <VPR heading END do not edit this line> ******************/

/*************** <auto-copyright.pl BEGIN do not edit this line> **************
 *
 * VR Juggler is (C) Copyright 1998-2003 by Iowa State University
 *
 * Original Authors:
 *   Allen Bierbaum, Christopher Just,
 *   Patrick Hartling, Kevin Meinert,
 *   Carolina Cruz-Neira, Albert Baker
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 *************** <auto-copyright.pl END do not edit this line> ***************/

#ifndef _VPR_Barrier_h_
#define _VPR_Barrier_h_

#include <vpr/vprConfig.h>

#if VPR_THREAD_DOMAIN_INCLUDE == VPR_DOMAIN_IRIX_SPROC
#  include <ulocks.h>
#  include <vpr/md/SPROC/Sync/BarrierSGI.h>
#elif (VPR_THREAD_DOMAIN_INCLUDE == VPR_DOMAIN_NSPR) || \
      (VPR_THREAD_DOMAIN_INCLUDE == VPR_DOMAIN_POSIX)
#  include <vpr/Sync/CondVar.h>
#  include <vpr/Sync/Mutex.h>
#  include <vpr/Sync/Guard.h>


namespace vpr
{

class SubBarrier
{
public:
   SubBarrier (int count, Mutex* lock)
      : barrierFinished(lock), runningThreads(count)
   {
   }

   CondVar barrierFinished; 

   int runningThreads;  
};

class Barrier
{
public:
   Barrier (int count)
      : currentGeneration(0), count(count), subBarrier1(count, &mutex),
        subBarrier2(count, &mutex)
   {
      //std::cerr << "vpr::Barrier::Barrier: Entering." << std::endl;
      subBarrier[0] = &subBarrier1;
      subBarrier[1] = &subBarrier2;
   }

   int wait(void);

   void addProcess()
   {
      std::cerr << "vpr::Barrier::addProcess: Not implemented yet."
                << std::endl;
   }

   void removeProcess()
   {
      std::cerr << "vpr::Barrier::removeProcess: Not implemented yet."
                << std::endl;
   }

private:
   Mutex mutex;   
   int currentGeneration;


   int count; 
   SubBarrier subBarrier1;
   SubBarrier subBarrier2;
   SubBarrier* subBarrier[2];
   // We keep two <sub_barriers>, one for the first "generation" of
   // waiters, and one for the next "generation" of waiters.  This
   // efficiently solves the problem of what to do if all the first
   // generation waiters don't leave the barrier before one of the
   // threads calls wait() again (i.e., starts up the next generation
   // barrier).

   // = Prevent assignment and initialization.
   void operator= (const Barrier &)
   {
      ;
   }

   Barrier (const Barrier &)
      : subBarrier1(0, &mutex), subBarrier2(0, &mutex)
   {
      ;
   }
};

} // End of vpr namespace

#endif  /* ! VPR_USE_IRIX_SPROC */

#endif  /* _VPR_Barrier_h_ */

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